Light anti-tank weapons



June 14, 1966 J. VILBAJO 3,255,668

LIGHT ANTI-TANK WEAPONS Filed June ll, 1964 4 Sheets-Sheet 1 MA N J. va'fzfijo mdoukfcktg lr ATT 0 RN E55 v June 14, 1966 J. VILBAJO 3,255,668

LIGHT ANTI-TANK WEAPONS Filed June 11, 1964 4 Sheets-Sheet 2 INVENTOR J, VL' Z ba 'o GLZM Q June 14, 1966 J. VILBAJO LIGHT ANTI-TANK WEAPONS 4 Sheets-Sheet 3 Filed June 11, 1964 J. Vii Z270 6kmx gem A-TTORNESS June 14, 1966 J. VILBAJO LIGHT ANTI-TANK WEAPONS 4 Sheets-Sheet Filed June 11, 1964 wQ g vil/1% \R R R .Q

H mm VLZb mwcu ATTORNESS United States Patent 3,255,668 LIGHT ANTI-TANK WEAPONS Jean Vilbajo, Brussels, Belgium, assignor to Contigea Societe Anonyrne, Brussels, Belgium Filed June 11, 1964, Ser. No. 374,387 Claims priority, application Belgium, June 25, 1963, 42,732, Patent 634,048; Apr. 23, 1964, 519,453, Patent 646,963

4 Claims. (Cl. 891.7)

The parties concerned are more and more interested in light weapons in order to increase the mobility of their units so as to increase at the same time the firing probabilities, which is the first constituent element of the probability of destruction.

This lightness factor necessarily prevents, to a certain extent, long range fire with an acceptable precision.

This lack of precision is due either to an insufficiently grazing trapectory, to an excessive duration of travel, to an excessive scattering of the initial speed or also to the fact that the projectile does not leave the gun in accordance with the direction to which the latter is trained.

When the weight of the gun is of the order of ten times the weight of the round of ammunition in its flight, the recoil speed of this weapon is of course very high and so is the recoil energy. In guns without normal recoil, this recoil energy is counteracted by a simultaneous thrust produced by a nozzle situated at the rear of the inner tube and which permanently equalizes the instantaneous momentum of the projectile. If there is a lack of balance between the two momentums, the tube will either recoil or move forward. The slightest unbalance or obliquity, which is impossible to avoid between the axis of the nozzle and the axis of the tube, gives rise to a force component which is at right angles to the firing direction and causes the Weapon to turn all the more easily when the moment of inertia of the latter is small, and this is so, because the weight is small as well as the length on account of considerations of weight and bulk. During the time which elapses between the moment of firing and the actual ejection of the ammunition from the Weapon, the latter must therefore move and the actual direction in which the projectile is being ejected is no longer that of the aim, which causes an exaggerated scattering.

It should also be borne in mind that on account of the fact that the Weapon can move forward or recoil up to several times before the projectile is actually ejected, there is a series of reactions on the bearings, thus changing the alignment of the tube and hence the direction in which the projectile leaves the gun.

It is of course possible to imagine a counter-recoil charge with very slow combustion rate such that, when this charge is fired together with the propelling charge of the projectile, the counter-recoil propulsion will be weak during the stay of the projectile in the gun, and therefore will bring little change in the aim of the latter; but as soon as the projectile has left the gun, this charge would reach a more important combustion rate so that the counter-recoil would then become very important.

There will still remain some irregularities due to this weak counter-recoil thrust, mainly due to the variations of combustion rate of the counter-recoil charge with the ambient temperature, which will alter the recoil velocity of the gun and hence the velocity of the projectile, so that there will be a substantial scattering of initial velocity.

The object of the present invention is to avoid all reactions on the tube as long as the projectile has not been ejected therefrom.

The tube recoils freely and this recoil is compensated as soon as the projectile has left the gun.

The complete operation thus takes place in the following way:

Firing of the normal charge, start of the projectile, recoil of the weapon whilst the projectile moves inside the tube, exit of the projectile, firing of the counter-recoil charge, finish of recoil and return to firing position.

These improvements will appear more clearly from the detailed description given below of a kind of ammunition and a weapon designed for applying the improvements according to the present invention. This description is given with reference to the appended drawings, of which:

FIGURE 1 shows a front view with partial section of a round of ammunition designed for applying the improvements according to the present invention;

FIGURE 2 shows on an enlarged scale the part indicated by F2 in FIGURE 1;

FIGURE 3 is a front view with partial longitudinal sections of a light weapon applying the improvements conforming to the present invention, the weapon being shown in the firing position;

FIGURE 4 is a top view with partial section of the arm illustrated in FIGURE 3;

FIGURE 5 is a view similar to that of FIGURE 3 whereby the weapon is illustrated in the position which it occupies when the projectile is just about to leave the tube of the gun;

FIGURE 6 is a view similar to that of FIGURE 3, whereby the weapon is shown in the position which it has at the moment when the projectile is ejected from the tube;

FIGURE 7 is a view similar to that of FIGURE 3, whereby the weapon is illustrated in the position which it occupies during the unlocking phase of the breech;

FIGURE 8 is an illustration on an enlarged scale of the part indicated by F8 in FIGURE 3;

FIGURE 9 is an illustration on an enlarged scale of the part indicated by F9 in FIGURE 5;

FIGURE 10 is an illustration on an enlarged scale of the part indicated by F10 in FIGURE 6;

FIGURE 11 is an illustration on an enlarged scale of the part indicated by F11 in FIGURE 7;

FIGURE 12 is similar to FIGURE 11 but after operation of the unlocking device.

In this form of embodiment, the round of ammunition consists in the present instance of a projectile 1 the rear part of which is engaged in a case 2 whose bottom comprises a priming device 3 of known design. Onto this bottom is fastened the counter-recoil charge 4, also conditioned in the well known way. In the present instance, aforesaid counter-recoil charge comprises a priming charge 5 connected to a delayed pyrotechnic firing device 6. This same priming charge 5 is connected to an electric firing device shown diagrammatically in 7. The electric circuit of this firing device is fed by a source or a generator of electricity 8 and controlled by a contact device 9 which can be operated by any pneumatic, mechanical, electric, magnetic or other means at the moment when the projectile actually leaves the barrel of the Weapon, aforesaid electric circuit being closed via the mass. In the present instance, the contact device 9 consists of a finger 10 fastened to the actual tube 11 of the weapon and of a contact or switch 12 fastened to the support 13 of aforesaid tube. This tube 11 bears on rings 14-15 and is designed so as to be able to recoil freely. Aforesaid support 13 of which aforesaid guiding rings 14-15 are parts, comprises amongst others, the trigger 16 of the firing device, known as such, for the charge of propellant, which is diagrammatically represented by 17 in aforesaid case 2, a bracket 18 capable of supporting the weapon and a means 19 for locking and for automatically unlocking the breech. Aforesaid breech, diagrammatically illustrated in 20, is disposed at the front part of a kind of nozzle 21 which surrounds, at a certain distance, the receptacle holding aforesaid counter-recoil charge 4 and extending the latter toward the rear of the weapon. Aforesaid breech 20 has, on the one hand, a peripheral shoulder 22 designed to fit against the corresponding peripheral part of plate 23 which forms the bottom of the receptacle for the counterrecoil charge 4, and, on the other hand, the diametrically opposed locks 24 which normally catch behind a terminal peripheral ring 25 of the actual tube 11 of the weapon. On account of this means, aforesaid breech 20 solidly connected to aforesaid nozzle 21 is fastened end-on and in the extension of the tube 11. On the other hand, aforesaid breech with its nozzle bears onto and is guided axially by two guide rails 26-27 of unequal length, in such a manner that, when this moving set has moved through a distance exceeding the length of the guide 27, which is the shortest, it can swivel about the guide 26 which is longer, thus releasing the adjacent end of the actual tube 11 of the weapon for making it possible to eject the case 2 and the elements connected thereto, and to introduce a new projectile of the type which has been described before. With-this object in view, aforesaid rails 26-27 are made directly dependent on the rear end of the actual tube or barrel 11 in such a manner that, when the breech 20 has been released, the latter as well as the nozzle 21 which it carries, can move along aforesaid rails. The locking mechanism 19 designed for providing an automatic unlocking and intended for co-operating with each bolt 24, consists in the present instance mainly of the levers 28 shaped as a longish triangle which can swing about a pivot 29 bearing onto the support 13 and permanently urged in opposition to aforesaid bolt 24 by a spring 30. About the same pivot 29 swings a moving stop 31 also urged against aforesaid lever 28 by a return-spring 32. This stop 31, of triangular shape, has a rounded angle 33 lying in the path of a cam 34 fastened to the actual tube or barrel 11. The relative position of these various elements, as well as their functions, will clearly appear in the following description of how the weapon designed in this way operates. Indeed, in the starting position, such as that which is illustrated diagrammatically in FIGURE 3, the projectile 1 is engaged in the actual tube or barrel 11, whereby the breech 20 closes hermetically the adjacent end of aforesaid tube, the closing tightness as illustrated diagrammatically in FIGURE 8 being ensured by aforesaid levers 28 which urge the locks 24 by means of studs 35. When the trigger 16 is pulled, the percussion or firing device, known as such, ignites the fuse 3 of the propelling charge 17. The projectile 1 moves axially in the barrel 11 which recoils freey, duly guided by the rings 14-15 (FIGURE This axial displacement causes that of the breech 20 or of the nozzle 21. The recoil of barrel 11 is not opposed by the earns 34 meeting the mobile stop 31, because these can freely swivel about their pivot 29 whilst tightening still more the return spring 32. In this way, the free recoil of barrel 11 can go on as long as there is a projectile in the latter. When the projectile leaves the barrel 11 (FIGURE 6), the cams 34 (FIGURE have gone past the mobile stop 31. The electric circuit of the fuse 7 is closed by the fact that, in the present instance, the elements 1.0-12 come into contact with each other, which causes the counterrecoil charge 4 to be ignited at the very moment when projectile 1 has left the weapon. At this moment, not only does the recoil come to an end, but the barrel and the elements which it carries are axially displaced in the opposite sense by the reaction effect of the gases which escape from nozzle 21.

In this return movement, the earns 34 meet and push back the mobile stops 31 (FIGURE 11) which, in turn, act on the corresponding levers 28 which, turning about their pivot 29, are brought to a level higher than the stud 35 which held they previously. As the recoil goes on,

aforesaid levers act as guiding path for aforesaid studs 35, which causes the bolts 24 to move out of the way and thus disengage the annular rear end 25 of barrel 11.

At the same time, the relative displacement between the breech and the guides 26-27 has moved aforesaid breech past aforesaid guide 27, which enables the breech and the nozzle which it carries, to tip over.

Preferably, when firing the propelling charge 17 by means of trigger 16, this charge has also fired the delayed pyrotechnic charge 6. The combustion of this pyrotechnic element has been predetermined in accordance with the time during which the projectile moves in the bore of the gun.

In this way, there are two means available for firing the counter-recoil charge 4, thus providing this weapon with a double safety.

The firing mechanisms and means are essentially variable, considering that they have no bearing on the improvements which are the actual object of the present invention and which consist essentially in designing aforesaid firing mechanisms and means in such a manner that the counter-recoil charge be ignited at the very moment when the projectile emerges from the barrel.

What I claim is:

1. A light gun for launching a projectile, said gun comprising a launching tube, a support slidably supporting said tube, a case enclosing a rear portion of said projectile, a propellant charge in said case, a counter recoil charge connected with said base, said propellant charge and said counter recoil charge constituting a round of ammunition, a priming device for firing said propellant charge, a trigger, means for firing said counter recoil charge substantially immediately after the projectile has left said tube, means operatively connecting said trigger with said priming device and said means, means preventing gases produced by the combustion of said propellant charge from producing a counter recoil action on said tube, and a rearwardly directed nozzle enclosing said counter recoil charge for producing a counter recoil action on said tube solely by gases produced by the combustion of said counter recoil charge.

2. A gun in accordance with claim 1, wherein the first-mentioned means comprise a finger connected to said tube and a switch connected to said support, said finger and said switch being located so as to engage each other immediately after the projectile has left said tube and wherein the second-mentioned means comprise a source of electrical current igniting said charges.

3. A gun in accordance with claim 1, wherein the first-mentioned means comprise a delayed action pyrotechnic firing device, the delayed action of said firing device causing the firing of said counter recoil charge substantially immediately after the projectile has left said tube.

4. A gun in accordance with claim 1, further comprising a breech located in front of said nozzle and means automatically releasing said breech when said tube after recoil moves to its position of rest.

References Cited by the Examiner UNITED STATES PATENTS 1,469,918 10/ 1923 De Maine 89-43 2,035,303 4/1936 Delacre 8942 FOREIGN PATENTS 19,332 1914 Great Britain. 471,891 9/1937 Great Britain.

BENJAMIN A. BORCHELT, Primal} Examiner.

SAMUEL W. ENGLE, Examiner, 

1. A LIGHT GUN FOR LAUNCHING A PROJECTILE, SAID GUN COMPRISING A LAUNCHING TUBE, A SUPPORT SLIDABLY SUPPORTING SAID TUBE, A CASE ENCLOSING A REAR PORTION OF SAID PROJECTILE, A PROPELLANT CHARGE IN SAID CASE, A COUNTER RECOIL CHARGE CONNECTED WITH SAID BASE, SAID PROPELLANT CHARGE AND SAID COUNTER RECOIL CHARGE CONSTITUTING A ROUND OF AMMUNITION, A PRIMING DEVICE FOR FIRING SAID PROPELLANT CHARGE, A TRIGGER, MEANS FOR FIRING SAID COUNTER RECOIL CHARGE SUBSTANTIALLY IMMEDIATELY AFTER THE PROJECTILE HAS LEFT SAID TUBE, MEANS OPERATIVELY CONNECTING SAID TRIGGER WITH SAID PRIMING DEVICE AND SAID MEANS, MEANS PREVENTING GASES PRODUCED BY THE COMBUSTION OF SAID PROPELLANT CHARGE FROM PRODUCING A COUNTER RECOIL ACTION ON SAID TUBE, AND A REARWARDLY DIRECTED NOZZLE ENCLOSING SAID COUNTER RECOIL CHARGE FOR PRODUCING A COUNTER RECOIL ACTION ON SAID TUBE SOLELY BY GASES PRODUCED BY THE COMBUSTION OF SAID COUNTER RECOIL CHARGE. 